Permission based rfid tag

ABSTRACT

An implantable, readable miniature transponder has an antenna coupled to a microchip integrated circuit. The integrated circuit has unique identifying information stored in the chip. The integrated circuit microchip also has control logic, a muscle stimulator, an EMG amplifier and a data transmitter. The integrated circuit is connected to the antenna and to muscle electrodes that have EMG sensors. When an external reader illuminates the transponder the control logic alerts the implanted subject and inhibits any data from being sent to the reader. Through a series of predetermined voluntary muscle contractions the subject sends a signal to the control logic to either allow or deny the reader access to the identifying information.

BACKGROUND OF THE INVENTION

This invention relates to the field of RFID tags. More specifically, adevice is described which allows a person to allow or deny access to apersonal identification tag.

The field of electronic identification of objects has been growing inrecent years. With the introduction of bar codes, the identification andinventory of objects has been advanced. Using a unique bar code, anobject can be scanned into a computer. The computer can make varioususes of the identified code, including pricing and inventory. Thetechnology for using bar codes is well known in the art.

Another type of electronic identification comprises small transpondersthat may be placed inside in an inanimate object such as a car, shirt ortool. Other identification transponders may be implantable into livetargets such as livestock, pets or laboratory animals. The transpondersprovide a convenient and almost fool proof method of identifying andkeeping track of the objects or animals.

Some transponders are “active,” having a power source of their ownintegrated into the circuitry. The active transponders normally are notsmall enough to be implantable. “Passive” transponders are capable ofbeing built in a very small package. Passive implantable transpondersused for identification purposes are often the size of a grain of rice.The passive transponders receive their power from the interrogator thatnot only powers the passive transponder but also reads the reply datafrom the implanted identification device.

An electronic identification system has several components. Theseinclude the RFID tag itself, an interrogation means (a reader) and acomponent that turns raw information (usually voltages) into data.

The identification tag contains an antenna, an integrated circuitcontaining unique identification data and receive/reply electroniccircuitry. This receive/reply circuitry is well known in the art and maytake many forms, depending on the precise requirements of the task.Different tags are known in the art. They include microchips that storethe unique identifiers, magnetic recording devices, bar codes orelectrical circuits that contain a number of resonant circuits. Thesetags can be energized and/or interrogated by an RF signal, a microwavesignal or an electrical or magnetic field, or by other suitable methods.Micron Communications or Biomark of Boise Id. and Texas Instruments ofDallas Tex. manufacture typical RFID tags.

An interrogator is used to probe the active or passive transponder. Inthe usual operation, the interrogator “illuminates” the transponder. Thetransponder will then respond with a signal that uniquely identifies thetransponder and, in some cases, with further information, such astemperature or glucose readings, for example.

The interrogator is linked to another electronic mechanism that canconvert the transponder's signal information to usable data. This datacollector usually takes the form of a data/computer interface. If aspecific unique identification code is sent to the interrogator,pre-loaded data such as the identity or origin of the specific objectmay be obtained. In animals, this data can include the name, weight,birth date, origin, or owner of the animal, for example. If thistechnology were to be used in humans, a person's personal data could bereadily integrated with the system to provide the user of properlyprogrammed interrogator nearly instantaneous detailed information on theperson who was “illuminated.” Providing this detailed information may ormay not be desirable. It is a prime object of this invention to allow aperson the option to grant or deny access to an implanted transponder.

The concept of using passive transponders to identify humans is notfar-fetched science fiction. With the already accepted use of suchimplantable transponders in animals the technology now exists to use thesame methods to identify humans. Voluntary implantation of RFID devicesin humans has already occurred and is the subject of over fifty USpatents. For example, U.S. Pat. No. 7,125,382 issued to Zhou in 2006describes a biosensor system that utilizes radio frequencyidentification technology. The biosensor system is specifically adaptedto monitor a physiological parameter of a patient using wirelesscommunication with an implanted transponder. U.S. Pat. No. 6,481,140discloses a transponder voluntarily implanted into a gun owner's handfor use in association with one or more guns. The transponder is uniqueand allows access to the firing mechanism of a pistol only when theimplanted transponder is in close proximity to the gun.

Obviously, there are good and bad uses for human-implanted RFIDidentifying tags. It could be useful to use such tags for children, forexample. If the child were kidnapped, an appropriately placedinterrogator could readily identify him or her. On the other hand, aperson having an implanted identification transponder would sacrifice agreat deal of personal privacy. Such a person could be readilyidentified at, for example, an airport or shopping mall. Thissurreptitious identification process could be quiet and virtuallyundetectable. It would be an advantage if illumination by aninterrogator could be made known automatically to the person with thetransponder. It is another object of this invention to allow a personhaving an implanted identification transponder to automatically be madeaware that an interrogation of his or her transponder is about to takeplace.

In many instances, a person having an implanted transponder would liketo permit access, in particular and limited situations, to the uniqueidentifiers in the transponder. For example, if the transponder wereimplanted to give the person access to a high security area, the personwould allow the interrogator to gain access to the identification data.On the other hand, in many situations (such as random checks at a mallor sports event) the person may want to either deny access to theforeign interrogator or to hide the presence of the implantedtransponder altogether. It is a still further object of this inventionto allow a person having an implantable identifying transponder toeither deny access to an interrogator or to hide the presence of thetransponder altogether.

Other and further objects of this invention will become obvious uponreading the below described specification.

BRIEF DESCRIPTION OF THE DEVICE

A radio frequency identification device (RFID) is integrated with anelectrical muscle stimulator and an electromyographic sense amplifier toproduce a specialized implantable RFID tag. When the identification tagis illuminated, a warning in the form of a slight muscle stimulus istransmitted to the human's muscles. The human may then decide whether ornot to allow the electronic interrogation to proceed. The Control Logicof the transponder is programmed to receive a command from the human.The human response command could be in the form of another musclecontraction, or a set of specified muscle movements. One set of humanmuscle contractions could give the command to allow the interrogation. Adifferent set of muscle contractions could give the command to denyaccess. If access were denied, the interrogator would read “notransponder present.”

BRIEF DESCRIPTION OF THE DRAWING

The drawing figure is a schematic block diagram of the invention showingthe Permission Based RFID system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An implantable passive transponder 1 has three main components, amagnetic coil (antenna) 2, two muscle electrodes 7 and an integratedcircuit. In the block diagram, everything located within the block 1(the implanted tag) is integrated into a single chip except the antenna2. The integrated circuit comprises elements of unique identifyinginformation, a power recovery circuit, a muscle stimulator, an EMGamplifier and control logic. The integrated circuit, physically a smallmicrochip, is of standard design and features. Using existing andwell-known methods, these components are packaged in a manner suitablefor implantation into the subject human. This packaging usually includesa sanitary and biologically safe material such as the glass transpondermanufactured by Biomark, Inc. other encapsulating materials includeceramic or metal exteriors. The muscle electrodes are normally made oftitanium or platinum.

The implantable transponder or tag 1 described herein is a passivetransponder, although the disclosure of this invention could also beapplied to active tags. The description of the tag as “passive” is meantas a disclosure of the preferred embodiment only and is not meant to bea limitation on the scope of this new invention. However, a passive tagcan be manufactured in a much smaller since size it has no battery orother power source. Due to the miniaturization aspects of a passivetransponder, it is more suitable for human implantation. The passive tag1 collects all of its operating power from the magnetic (used at lowfrequencies of 10-500 kHz) or electromagnetic field (used at RFfrequencies of 400 MHz-2 GHz). The reader or interrogator emanates thepower. Typically, a coil wound around a ferrite core, commonly known asan antenna 2, collects the power.

When an external reader (interrogator) 10 attempts to interrogate theimplanted tag (transponder), it illuminates the human with a magnetic orelectromagnetic field. The magnetic coil of the antenna 2 produces anelectrical current from which power is recovered by the power recoverycircuit 3. The power recovery circuit 3 is part of the integratedcircuit design of the implanted unit. Such circuits vary widelydepending on use, but are well known in the art. The power recoverycircuit 3 provides power for all circuits within the implanted tag. Theintegrated circuit (IC) also contains the unique identifying subjectinformation 4 that is protected from unwanted intrusion by thisinvention.

Under normal operating conditions heretofore known in the art, theidentifying information 4 of the tag 1 is transmitted to the reader oncethe tag is illuminated and the circuit energized. However, thisinvention discloses an electronic security method that preventstransmission of the unique identifying information until certainconditions are met. The operative conditions to release the information,or to deny access to it, are described below and constitute the noveldisclosure of this specification.

The IC contains control logic 5. Once the subject is notified that histransponder has been illuminated, the control logic 5 holds the uniqueidentifying information 4 until certain conditions are met. The subjectcontrols these conditions. The subject may either permit or deny accessto the information based on muscle responses.

Once power is applied to the tag 1 (by the external reader) 10, thecontrol logic 5 becomes aware that an external reader 10 is attemptingto interrogate the tag. The control logic 5 commands the musclestimulator 6 to apply the stimulus to the subject's muscles.

The muscle stimulator 6 is also part of the IC. Muscle stimulators arewell known in the art. As used in this device, a muscle stimulator sendssmall electrical currents to muscle electrodes 7. At least two muscleelectrodes are needed to practice this device. The small stimulation ofthe muscle is the warning or alert signal that notifies the humancarrier that his transponder has been illuminated and that an attempt isbeing made by an outside interrogator to access the unique identifyinginformation contained in the transponder. The stimulus would consist ofa train of electrical impulses that produce mild contractions of thesubject's muscle. The cadence of the alert stimulus pulses is chosen toproduce an easily identifiable yet harmless sensation in the subject.The sensation would be similar to the vibrating alert of a cell phone,but the source of the vibration would be located within the humansubject. Once the subject is alerted to the attempt to read the uniqueidentifying information of the tag, the subject can respond to eitherallow or deny access to the identifying information by flexing one ormore muscles in one or more patterns.

The electromyographic sensors of the muscle electrodes are in intimatecontact with a selected voluntary muscle, typically in one of thesubject's extremities such as the forearm. Electromyographic sensorsdetect small signals resulting from the contractions of muscles. EMGsare a well-understood phenomenon of muscle tissue. When a given musclecontracts, a small corresponding electrical signal occurs. Anelectromyogram sensor is well understood in the art can detect such asignal. Such sensors typically provide an output voltage thatcorresponds to the strength of the musculature electrical signal. Twomuscle electrodes will measure different voltages. The differencebetween the two voltages is measurable and can be used to make thisdevices function as described. EMGs will provide signals of varyingmaximum magnitudes when placed in contact with virtually any muscle.

EMG sensor technology has been used with positive results in manydifferent fields, but most particularly in the field of paralysis.Humphrey describes a system, method and device for controlling externaldevices (for example, prosthesis, roots or robotics, and for thestimulation off muscles of paralyzed individuals) by signals derivedfrom very small sensors or an array of sensors in U.S. Pat. No.6,171,239. Humphrey uses bundles of six to ten small (20-50 micrometersin diameter) insulated and flexible noble metal wires as muscleelectrodes. The various components of such a system are described in theHumphrey specification and other patents. Humphrey has a detaileddescription of the EMG sensors and electrodes, electronic microchips,external receivers and demultiplexers and the electronic methods used toshape and calibrate the signals.

For a discussion of the well known electronic characteristics of acircuit that uses EMGs to send wireless muscle signals to an externalreader see the U.S. Pat. No. 7,148,878 issued to Hong.

An EMG amplifier 8 is also included in the integrated circuit of thedevice. Between and after the alert stimulus, the EMG amplifier 8 worksto detect voluntary muscle contractions of the subject's muscle. Thecontrol logic 5 of the implanted tag can thereby measure the subject'svoluntary response to the alert stimulus. The control logic 5 may beprogrammed in a variety of different ways to carry out this invention.For example, the control logic could be programmed to recognize aspecific sequence or cadence of voluntary muscle contractions to confirmthat the subject is consciously responding to the alert stimulus. Thevoluntary muscle contraction cadence could be as simple as a singlecontraction such as that produced by clenching a fist. Alternatively, itcould be required that the contraction sequence be an arbitrarily longsequence of contractions of pre-specified duration and time spacing. Thesubject could even be required to spell out a word in Morse code byclenching a fist in a certain sequence for certain durations (dot anddash) before the control logic would recognize the response. Thisadditional layer of security would be particularly useful in preventingmanipulation of an unconscious individual.

Once the control logic has recognized a subject response in the form ofvoluntary muscle contractions, two operational modalities exist: Allowread or Deny read. The subject's response to the control logic throughthe EMG amplifier 8 would determine which of the two states isacceptable.

The transponder unit communicates with the external reader 10 by thedata transmitter 9. The data transmitter 9 is also part of theintegrated circuit design.

The interrogator (reader) 10 includes sufficient radiated power toenergize the transponder at the desired read rates, sufficient bandwidthto interrogate the device in a reasonable amount of time, sufficientsensitivity to accurately obtain the device response and a suitableinterface to a computer to record and update a database. Energizing thetransponder device can be accomplished by transmitting anelectromagnetic (DC, wave or field) or acoustic signal in the form of acontinuous wave, pulsed cw wave, chirped waveform, spread-spectrumwaveform, impulse or coded waveform.

When a certain specified signal is sent (as, for example two shortclinches of the fist followed by one of longer duration) a “Permit Read”modality is given and the control logic would release the uniqueidentifying information to the external reader via the data transmitter.

If, on the other hand, the subject gives the control logic the signal todeny read (such as, for example, by sending one short fist clinch andtwo long fist clinches) the control logic will prevent an otherwiseautomatic release of the identifying information.

The implantable transponder device described herein is the preferredembodiment of the device. The basic new and novel concept of thisinvention consists in giving the human subject the option to allow ordeny access to information found on an identifying implanted tag.Generally, the use of an identifying and readable implantabletransponder containing an antenna and a specialized microchip, poweredby an external interrogator/reader, is known in the art. However, addingthe circuit elements that allow the subject to grant or deny access tothe information contained in the transponder by voluntary musclecontractions is new. Using this method of RFID control it is nearlyimpossible for an external reader to detect the presence of an implanteddevice if permission to read is denied by the subject.

It is to be appreciated that the specification herein is meant as anillustration only and not as a limitation. The concept of subjectcontrol of the implanted information can also be used with activetransponders. It can also be utilized if the reader is hard wired to theidentifying device and with varying modes of energizing the identifyingdevice.

1. An implantable transponder system for a human subject capable ofbeing read by an external reader, comprising: (a) an antenna; (b) anintegrated circuit electrically connected to said antenna comprisingidentifying information, power recovery, control logic, a musclestimulator, an EMG amplifier and a data transmitter; (c) at least twomuscle electrodes having EMG sensors, said electrodes being electricallyconnected to said integrated circuit and in intimate contact with atleast one muscle of said subject.
 2. An implantable transponder systemfor a human subject capable of being read by an external reader as inclaim 1, wherein said transponder is powered by radiation from saidexternal reader.
 3. An implantable transponder system for a humansubject capable of being read by an external reader as in claim 1,wherein said control logic stimulates at least one muscle of a subjectwhen said transponder is illuminated by an external reader.
 4. Animplantable transponder system for a human subject capable of being readby an external reader as in claim 1, wherein said control logic allowsor denies the external reader access to said identifying informationafter receiving a signal from said subject.
 5. An implantabletransponder system for a human subject capable of being read by anexternal reader as in claim 4, wherein said signal is generated when thesubject contracts at least one of said muscles in a set pattern.
 6. Animplantable transponder system for a human subject capable of being readby an external reader as in claim 1, further comprising two or moremuscle electrodes.